Donald Trump talks during a large rally inside the American Airlines Center as part of his campaign stop in Dallas, Texas on Sept. 14, 2015. Photo Credit: EPA / Larry W. Smith

DALLAS - Renewing his charge against illegal immigration, Republican presidential candidate Donald Trump on Monday called the United States "a dumping ground for the rest of the world" as he rallied thousands of Texas supporters behind his fiery candidacy and promised Republican leaders he's just getting started.

Despite calls from GOP officials to tone down his rhetoric on the sensitive issue, the GOP front-runner decried "anchor babies" and gang members among the immigrants living in the U.S. illegally, drawing huge ovations from a rowdy audience packed into Dallas' American Airlines Center. The 20,000-capacity venue that was at least three-quarters full for the evening rally.

"It's disgusting what's happening to our country," Trump continued as he called for more legal immigration.

Provocative rhetoric on immigration has defined Trump's presidential campaign from the very beginning, when the billionaire businessman called Mexican immigrants rapists and criminals in his June announcement speech. Republican National Committee Chairman Reince Priebus, among others, has encouraged Trump to soften his tone, yet the former reality television star has refused.

The strategy may play well among the GOP's more conservative voters -- those who filled the Dallas sports arena among them -- yet threatens to hurt the party's standing among a growing group of Hispanic voters in the general election.

"This is a movement that's happening," he declared, confronting critics who think he's not running a serious campaign. "Now it's time to really start, because this is going to happen, I'm telling you, I'm not going anywhere."

"Unless I win, it's been a waste of time for me, folks," he continued.

Monday night's crowd ate it up.

They waved miniature American flags, munched nachos and drank $13 cups of beer from plastic cups as they interrupted Trump repeatedly with applause.

"Sometimes he puts his foot in his mouth, just like everybody," said Barbara Tomasino, a 65-year-old retired elementary school librarian from Plano, Texas, who donned a dress, shoes and a purse plastered with pictures of Trump's face. "If he gets elected, he might need to tone it down a little bit."